admonish vs put on guard

admonish

verb
  • To inform or notify of a fault; to rebuke gently or kindly, but seriously; to tell off. 

  • To advise against wrongdoing; to caution; to warn against danger or an offense. 

  • To instruct or direct. 

put on guard

How often have the words admonish and put on guard occurred in a corpus of books? (source: Google Ngram Viewer )